Washing of cans and the like



Oct. 1950 v. SCHWARZKOPF EI'AL 2,

WASHING OF CANS AND THE LIKE Filed June 30, 1943 I ll Ill ll 3 iii/emPatented Oct. 17, 1950 WASHING OF CANS AND THE LIKE Vergil Schwarzkopfand Walter H. Paulson, Chicago, Ill., assignors to The Lathrop-PaulsonCompany, Chicago, 111., a corporation of Illinois Application June 30,1943, Serial No. 492,812

3 Claims.

This invention relates to the washing of cans and the like, and moreparticularly to a method for improving the WaShing and especially therinsing of the surface of cans.

An object of the invention is to provide for the treatment of cans, suchas milk cans and the like, with water at a relatively high tempera ture,such as water heated under pressure to a temperature above the normalboiling point thereof. Another object is to provide in the treatment ofcans with water, a solution for preventing the precipitation of lime andother elements which would otherwise be precipitated in the hot watertreatment. Still another object is to provide a solution which producesan improved rinsing or washing elTect and at the same time prevents theprecipitation of lime and other elements of hardness in the water. Afurther object is to treat water with a reagent which decreases thesurface tension and increases the flow qualities of the water and at thesame time prevents the precipitation from the water at elevatedtemperatures of lime and the like.

The invention is illustrated in the accompanying drawing, in which Fig.1 is an elevational view partly in section showing the apparatus used inthe invention; Fig. 2 is a longitudinal sectional view of the injectioncylinder; and Fig. 3 is an elevational view partly in section showingthe recycling apparatus used in the invention.

In the embodiment of the invention described herein, a tank Incontaining a solution II of the reagent with which the water is to betreated is provided with an outlet conduit I2 leading to a check valvel3 and a. conduit M which communicates with a cylinder l5 for injectingthe solution into a water stream. A conduit [6 extends from the cylinderl5 to a check valve [1 and thence to a conduit is leading from a waterinlet IS.

The cylinder I5 is provided with a piston having rings 2| fittingtightly within the cylinder. If desired, leathers may be used instead ofthe rings 2| to bring the piston 29 into tight engagement with thecylinder. The piston rod 22 extends through the closed end 23 of thecylinder and may be adjustably secured at 24 to a bracket 25 forengaging an upwardly-extending arm 26 of the drive mechanism. A thumbscrew 21 may be used to adjust the position of the arm 26 within therecess 28 in the bracket 25.

T e a 6 ay be m unted on a shaft Z9 which is reciprocated by mechanism(not shown) at predetermined intervals. Preferably, the shaft 29 ismounted on a conveyor mechanism for advancing cans which are to bewashed and is synchronized in its movement with the movement of theconveyor mechanism so that each time a can is advanced one step alongthe conveyor mechanism, the piston moves to inject the solution into thewater stream.

The rearward movement of the piston 20 away from the conduits I4 and [6causes the solution.

to be drawn through the check valve I3 to the cylinder l5 while thecheck valve [1 prevents the flow of water into the cylinder. The forwardmovement of the piston, on the other hand, causes the solution to passthrough the check valve l 1 and to be injected into the water stream inthe conduit l8, while the check valve l3 prevents the flow of solutionto the conduit l2.

The reagent in the solution in the tank I0 may consist of any suitablewater-miscible solution for preventing the precipitation of lime and thelike from the water as the temperature of the water is raised and forimproving the rinsing and cleaning qualities of the water. Thus, thesolution may contain a, suitable acid to decrease the alkalinity orprovide a mildly acid reaction in the water and also a wetting agent fordecreasing the surface tension of the water solution.

A suitable solution which may be employed includes, in addition to thewater, gluconic acid or other suitable acid for imparting a definiteacid reaction to the water or for at least decreasing the alkalinity ofthe water, and a wetting agent such as a sulphonated alcohol orsulphonated petroleum fractions. For example, such an aqueous solutionmay consist of .9% gluconic acid and .1% of the wetting agent sold underthe trade name of Santomerse S. The acid may be present in sufficientquantity to provide a final water solution in which the alkalinity ofthe water is substantially decreased. Preferably, the rinse solution hasa pH of between 6 and 8. The solution of the acid and wetting agent maybe used in the tank in a concentration of approximately 1% to 2 Thesolution may be mixed with water according to the ratio of approximately3% of a 1%% solution. Any suitable or desirable proportion of thereagent or solution may of course be used.

The conduit [8 carrying the stream of water and receiving the solutionintroduced from the conduit [6 and check valve I! may lead through aconduit 30 to an enlarged pie-heating conduit 3| extending through thetanks 32 and 33. The tanks 32 and 33 may contain heated water to therespective levels 34 and 35 so as to impart heat to the solution withinthe enlarged conduit 3! extending therethrough. The tanks 32 and 33communicate through an overflow conduit 36 which permits heated water inthe tank 33 to flow into the tank 32. A conduit 3| extends through thepartition 31 between tanks 32 and 33.

From the enlarged conduit 3|, the pre-heated solution passes through apipe 38 to a valve 39 and thence to an inlet 53 for the recirculatingsystem 4|. Steam from the line 42 is passed through the conduit 43through the valve 44 to an inlet 45 for the recirculating system 4|.

As seen particularly in Fig. 3, the recirculating system 4| includes asteam inlet elbow 43 to which is threadedly secured a steam nozzle 41.The steam nozzle, in turn, threadedly engages a water inlet bulb 48which communicates with a mixin chamber 49. An outlet 50 from the mixingchamber 49 communicates with a coupling lead ng to a recycling pipe 52and the heated water outlet 53.

The housing or casing 54 about the mixing chamber 49 communicates witha, water inlet elbow 55 so that water may be introduced into the spaceabout the mixing chamber. The conduit 56 communicating with the otherside of the housing 54 provides an inlet into the horsng for the heatedwater which is recycled through the conduit 52.

When water from the inlet 40 passes through the elbow 55 into thehousing 54 and about the mixing chamber 49, it is permitted to flowtoward the end of the housing having the steam nozle therein, and passesthrough the ports 51 int the water inlet bulb and thence, w th thesteam, from the nozzle 41 into the mixing chamber 49, in which the waterand steam are mixed. The m xture passes from the mixing chamber 49through the outlet 50 to the coupling 5|, and a portion of the mixtureis then recycled through the conduit 52 and through the recycling inlet55 into the housing 55. This porton of the highlv heated water may flowthrough the ports 51 into the water in et bulb 4S and thence to them'xing chamber 49.

Anv suitable pressure mav be used to o tain the desired temperature ofthe water. With a. water pressure of approximately 23 pounds, atemperature of the liqu d water of approximate y 225 F. is obtained. Thesteam may be introduced into the chamber under pressure which exceedsthe Water pressure in order that the steam may be read ly introducedinto the chamber and mixed with the water. Preferably, the steampressure is substantially above the water pressure. This temperature ofthe steam, of course, is also substantially above that of the waterwhich is being introduced and is also above the final temperature of thewater. For example, if the water pressure is approximately 23 pounds, asteam pressure of approximately 40 pounds may be used. At this pressure,the temperature of the steam will be approximately 267 F. as comparedwith a final Water temperature of 225 F.

The valves 39 and 44 are used to control the flow of the water solutionand steam into the recycling apparatus 4|. The valves which may be ofany suitable or conventional type are provided with plungers, such asthe plunger 58 on the valve 35 and the plunger 59 on the valve 44, whichserve to control the valves. A depending member 60 on the shaft 29 maybe provided with bosses 6| and 62 for engaging the plungers of thevalves. The device may be readily synchronized so that the reciprocationof the shaft 29, which is synchronized with the movement of the cans inthe washing machine, not only operates the injection cylinder |5 butalso controls the valves 39 and 44.

From the outlet 53 of the recycling apparatus, the highly heated waterpasses through the nozzle 63 into the interior of the can. Although thewater may be heated to a temperature in the neighborhood of 225 F., byreason of the presence of the reagent therein, no substantialprecipitation of lime or other similar materials occurs.

The device is preferably used in the rinsing of cans which have alreadybeen subjected to a cleaning action. When the can to be rinsed issubjected to the spray of extremely hot water containing the reagent,the rinsing is quickly and efiiciently accomplished. The water, byreason of the presence of the Wetting agent, has a low surface tensionand flows readily over the surface of the can. By reason of this, thefilm of water formed on the can after the r'nsing operation is extremelythin, and at the temperature to which the can is raised by contact withthe superheated water, is evaporated almost instantaneously.

With the present invention, the Water may be heated to a temperaturesufliciently high to dry the can to which the water is applied almostinstantaneously when the water on the surface of the can is in theextremely thin film produced by the solution used. At the same time,despite the high temperature to which the water is heated, there is noprecipitation of lime or other insoluble salts in the course of thetreatment. Accordingly, a quick and eifective high temperature rinse isobtained. Since the temperature of the can may be raised to atemperature slightly beow the normal boiling point of Water by contactwith the superheated water from the nozzle, the treatment also serves tosterilize the can to which the solution is applied.

Although the invention has been described in connection with a specificembodiment, it will be apparent that modifications and changes may bemade without departing from the spirit and scope of the invention.

We claim:

1. In a process for treating cans in which a can is supported above apool of hot water and into which water employed in washing the caninterior is discharged, the steps of mixing with Water a reagent forpreventing the precipitation of lime therefrom, said reagent alsoreducing the surface tension of the Water, passing the waterreagentmixture in a confined stream through said pool of hot water to preheatthe mixture, then further heating the mixture under superatmosphericpressure to a temperature above the normal boiling point of water, andapplying the solution to the surface of the can.

2. In a process for treating cans in which a can is supported above apool of hot water and into which water employed in washing the caninterior is discharged, the steps of mixing with water a reagent forpreventing the precipitation of lime therefrom, said reagent alsoreducing the surface tension of the water, passing the waterreagentmixture in a confined stream through said pool of hot water to preheatthe mixture, then further heating the mixture under superatmosphericpressure to a temperature in the neighborhood of 225 F., and applyingthe solution to the surface of the can.

3. A method of treating a container, comprising mixing with water anorganic acid for-preventing the precipitation of lime and the liketherefrom, heating the solution with steam under superatmosphericpressure to a temperature in the neighborhood of 225 F., andapplyingsuch solution at a temperature not below the normal boilingpoint of water upon the container surface while substantially preventingthe deposition of lime.

VERGIL SCHWARZKOPF. WALTER H. PAULSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

